Is earth a good place to look for the oldest rock in the solar system? Why or why not?

Chrondritic meteors are left over from the formation of the solar system 4.5 billion years ago, and have not gone thru the crustal melting and reformulation that you find on terrestrial planets. The gas giants may have a solid core but they are likely metallic hydrogen or helium or perhaps carbon. So if you find a stony meteor, its pretty sure to be really old.